Mention the type of host cells suitable for the gene guns to introduce an alien DNA.

Undifferentiated plant cells are the most suitable host cells for the gene guns to introduce on alien DNA.

Reason: Because gene gun originally designed for plant transformation. Gene gun is a device for delivering exogenous DNA to cells. And plant cells have rigid cell wall which can be easily broken down by bombarding them with high velocity micro-particles of gold or tungsten coated with DNA in a gene gun.